Field of the Invention
The subject of this invention is a hollow vane, as well as its associated production method.
The vane in question can be an OGV (Outlet Guide Vane), i.e. a fixed vane of a rectifier of the flow of the gases, downstream of a stage of mobile vanes belonging to the rotor of a turbomachine, without other types of vanes being excluded.
Description of the Related Art
Vanes can be solid, or on the contrary hollow when it is desired to reduce their weight. They then comprise an internal cavity and are often built in two portions: a main portion that encompasses the cavity, comprising an open face in order to make it possible to access the cavity, and to produce it via machining, and a cover that is assembled to the main portion, in such a way as to close the opening and to form a smooth and continuous external face, required for correct aerodynamic operation of the vane. Documents FR 2 956 875 A and FR 2 978 196 A can be mentioned to show certain known designs of hollow vanes.
The conventional modes for assembly between the cover and the main portion are welding and gluing. However these two modes for assembly both have certain disadvantages: the welding is accompanied by a mechanical reduction on the welded joint relative to the properties of the base material of the vane, residual constraints and deformations in the vane, and entails expensive machining operations in order to rectify the shape of the external face; and the gluing can have an uncertain resistance over long periods of time, is rather subject to the propagation of cracks, as soon as they appear, as to the attack of certain chemical agents, and often imposes extra material in order to guarantee the junction of the parts over the entire edge, which exceeds the joint and which must be removed after the hardening in order to recover the smooth external face that is indispensable for a vane. Inspections concerning the quality of the assembly are required, and the replacing of the cover during maintenance campaigns is difficult or impossible. This is why an improvement in the assembly was sought. It forms the subject of the invention.